Mucinous cystic neoplasms (MCN) and serous cystic neoplasms (SCN) account for a large portion of solitary pancreatic cystic neoplasms (PCN). In this study we implemented a convolutional neural network (CNN) model using ResNet50 to differentiate between MCN and SCN. The training data were collected retrospectively from 59 MCN and 49 SCN patients from two different hospitals. Data augmentation was used to enhance the size and quality of training datasets. Fine-tuning training approaches were utilized by adopting the pre-trained model from transfer learning while training selected layers. Testing of the network was conducted by varying the endoscopic ultrasonography (EUS) image sizes and positions to evaluate the network performance for differentiation. The proposed network model achieved up to 82.75% accuracy and a 0.88 (95% CI: 0.817–0.930) area under curve (AUC) score. The performance of the implemented deep learning networks in decision-making using only EUS images is comparable to that of traditional manual decision-making using EUS images along with supporting clinical information. Gradient-weighted class activation mapping (Grad-CAM) confirmed that the network model learned the features from the cyst region accurately. This study proves the feasibility of diagnosing MCN and SCN using a deep learning network model. Further improvement using more datasets is needed.

Background: Gastrointestinal tumor bleeding remains a clinical challenge because it is difficult to treat with conventional endoscopic hemostatic options. Recently, an endoscopic hemostatic powder (UI-EWD) was developed and reported to provide effective control of upper gastrointestinal bleeding. The aim of current study was to evaluate the feasibility and efficacy of this novel hemostatic powder in tumor bleeding. Methods: A total of 41 consecutive patients with upper gastrointestinal tumor bleeding were included. UI-EWD was applied in all patients as an auxiliary hemostatic method as a salvage therapy or monotherapy during endoscopic treatment. Hemostasis success rates, adverse event related to UI-EWD, and rates of re-bleeding were evaluated. Results: In all cases, UI-EWD application was successful at tumor bleeding sites. Immediate hemostasis occurred in 40/41 (97.5%) patients, and re-bleeding within 28 days occurred in 10 of 40 (22.5%) patients that achieved initial hemostasis. The success rate of immediate hemostasis for UI-EWD monotherapy was 100% (23/23). The re-bleeding rate at 28 days after UI-EWD monotherapy was 26.1% (6/23). No adverse events associated with UI-EWD application were encountered. Conclusions: The success rate of UI-EWD for immediate hemostasis in cases of GI tumor bleeding was excellent and UI-EWD produced promising results with respect to the prevention of re-bleeding. Based on these results, we suggest that UI-EWD be considered an effective salvage therapy or even monotherapy for GI tumor bleeding.

Background. von Hippel–Lindau (VHL) disease is an autosomal dominant disorder characterized by the development of multiple tumors in the central nervous system and visceral organs. In this study, we describe clinical features of pancreatic involvement in VHL disease, of which there have been few reported studies to date. Methods. We reviewed medical records of 63 VHL patients, diagnosed at Asan Medical Center between January 1995 and December 2013. Demographic, genetic, and radiologic features, and the clinical course of VHL patients with pancreatic involvement were retrospectively analyzed. Results. Among the 63 VHL patients, 55 (87.4%) had VHL-associated pancreatic lesions (male: female, 31:24; median age at onset, 33 years; range, 12–67 years). These presented as single simple cysts (n = 5, 9.1%), multiple simple cysts (n = 14, 25.5%), serous cystadenoma (n = 29, 52.7%), or neuroendocrine tumors (NETs) (n = 17, 30.9%). Genetic tests were performed on 35 of the 55 patients (63.6%) and VHL gene mutations were observed in 28 of them (80%). Of the 55 patients, 11 received surgical treatment, 2 received endoscopic ultrasonography-guided ethanol ablation therapy as local treatment for NET, and 42 patients were followed regularly without intervention (20%, 3.6%, and 76.4%, respectively). Conclusion. Pancreatic involvement in VHL disease is common, with a prevalence of 87.4%. Serial screening imaging studies for the early detection of VHL-associated NET are necessary in individuals at risk of VHL disease. A large-scale epidemiological study of VHL disease is needed to examine the natural course of the disease and the prognosis for pancreatic involvement.

Kim B, et al. J Korean Med Sci. 2021 Mar;36(15):e94. https://doi.org/10.3346/jkms.2021.36.e94

Hypoxemia can occur during endoscopic retrograde cholangiography (ERCP) and it is difficult to achieve adequate ventilation with the prone position. High-flow nasal oxygen (HFNO) has been recommended to be more effectively help ventilation than conventional low flow oxygen. The aim of this study was to evaluate the effect of HFNO during sedated ERCP and to identify predictors of desaturation during ERCP. The investigated variables were age, gender, American Society of Anesthesiologists classes (ASA), duration of exam, and sedative used for midazolam or/and propofol of 262 patients with sedated ERCP. The differences between categorical and continuous variables were analyzed using the Student’s t test and the chi-square test. Desaturation (SpO₂ ≤ 90%) occurred in 9(3.4%) patients among 262 patients during sedated ERCP. The variables found to predict desaturation were older age (p < 0.01), higher sedation dose for midazolam or propofol (p < 0.01), and use of midazolam (p < 0.01). Desaturation rate was lower during sedated ERCP with HFNO compared to the preliminary study with conventional low flow nasal oxygen. Patients with older age, higher sedation dose, or the use of midazolam might require close monitoring for desaturation and hypoventilation by nursing staff. The study shows the use of high-flow nasal oxygen reduces the incidence of desaturation during ERCP.